title: Salivary gland mucoepidermoid carcinoma is a clinically, morphologically and genetically heterogeneous entity: a clinicopathological study of 40 cases with emphasis on grading, histological variants and presence of the t(11;19) translocation.
abstract: OBJECTIVE
  To correlate World Health Organization (WHO) grade, patient's outcome and presence of t(11;19) to histological tumour variants in 40 well-characterized mucoepidermoid carcinomas (MECs).
  
  
  RESULTS
  MECs were classified as 'classical' based on the presence of equal proportions of the three cell types or the dominance (≥50%) of mucous cells together with at least one other cell type, and as 'variant' if composed of ≥80% of a single non-mucous cell type. Classical MECs were more common (n=23). Variant MECs had predominant squamoid (n=9), eosinophilic (n=5) or clear cell (n=3) morphology. Twenty-seven tumours were WHO grade 1, three grade 2 and ten grade 3. The t(11;19) was detected in 82%, 35% and 0% of classical MEC, variant MEC and non-MEC, respectively. Classical MECs were associated significantly with age ≤60 years (P<0.001), grade 1 (P<0.001) and t(11;19) (P=0.003). Short overall survival was associated significantly with age >60 years (P=0.001) and Union for International Cancer Control (UICC) stage >I (P=0.031), residual tumour (P<0.001), tumour grade >1 (P=0.001) and squamoid variant (P=0.002) in Kaplan-Meier analysis.
  
  
  CONCLUSIONS
  The results underscore the great histological diversity of MEC, the reproducibility of the WHO grading criteria and the value of histological subtypes as an additional prognostic factor.
authors.affiliation: Department of Pathology, University of Erlangen, Erlangen, Germany. stephan.schwarz@uk-erlangen.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Schwarz
authors.forename: Clemens
authors.initials: C
authors.lastname: Stiegler
authors.forename: Maximilian
authors.initials: M
authors.lastname: Müller
authors.forename: Tobias
authors.initials: T
authors.lastname: Ettl
authors.forename: Gero
authors.initials: G
authors.lastname: Brockhoff
authors.forename: Johannes
authors.initials: J
authors.lastname: Zenk
authors.forename: Abbas
authors.initials: A
authors.lastname: Agaimy
mesh_terms: D000704:Analysis of Variance; D018277:Carcinoma, Mucoepidermoid / Q000235:genetics / Q000473:pathology*; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D016001:Confidence Intervals; D003937:Diagnosis, Differential; D005260:Female; D005858:Germany; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D012468:Salivary Gland Neoplasms / Q000235:genetics / Q000473:pathology*; D012469:Salivary Glands / Q000473:pathology; D013997:Time Factors; D014178:Translocation, Genetic / Q000235:genetics